You've definitely gotten through the hardest parts. I wonder if she was extra emotional since she could tell something was up for a while. The anxiety from that unknown could have definitely fed that reaction but hopefully it will dissipate quickly. (and another F him for feeling blindsided. ridiculous to be blindsided by a situation you yourself have caused).
It is indeed very hard, but I agree with the rest, you've been handling this quite well. She'll see that and appreciate it.
I really think this was the case. She's very perceptive about what's going on around her and I think she needed to know, but of course it wasn't the thing she was hoping to hear.